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The time-area method holds for cox RC engines up to ship engines. You don't have to be spinning an engine at crazy piston speeds for it to be applicable. I'd be concerned about uneven cylinder charging if using crankcase compression as well as a turbo on a v-twin. A centrifugal pump geared to the crank actually provides the right pressure ratio from starting to max revs...

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Time- area is a way to control that wanted charge velocity is not going near to sonic somewhere.
If Harley could get 40 horsepower past an exhaust valve of ca 40mm so can we.
My concept needs that pistons are same mass but not diameter.
The two exhaust valves and inlet porting belts can have different sizes and timings.

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Charge and exhaust velocity need to be at certain levels to get good BMEP. 2 strokes just don't work well away fron those values. 4 strokes can get away with smaller valves for a smaller penalty as the piston pumps the charge in and out.
You will have no problem with the transfer ports, the exhaust will be the limiting factor on your long stroke design. You'll need to run some numbers.

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You're gonna want forked connecting rods so you don't get that annoying rocking motion two-cylinder boxers have.
Pretty much all V-twins use them.

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My phantasy engine use crankcase for charge pumping as do all desent two strokes.
That means caged rollers between hard crankpins and rods.
All V cylindered two stroke outboards do it by having cracked-parted connecting rods and a one piece crank
Harleys had undivided conrods and made crank up from parts screwed together.
For sizing of components we can do worse than study Yamahas V6 HPDI 250 outboard.
Two of its 93mm bore cylinders make 83 horsepower at 5000 rpm and strokes 82 mm at a pme of 7 bar.
They evidently have exhaust ports big enough to pass 40 horsepower per cylinder.
If I double their stroke and run 2400 rpm they do what I want:ca 40 horsepower at 2400 rpm from a 92mm piston.
From memory the crankpin diameter is 40mm and width of a conrod assembly is 20mm.
If I chose 50mm diameter and 16mm width , this will be double as longlived as the Yamaha because I only run half as fast.
Rigth or wrong I prefer undivided conrods and built up cranks.
So be it.
Single throw two stroke cranks are mostly made by pressing parts together.
Cheap,heavy and also act as flywheel.
Especially on Harleys.
We do not need flywheel in a ungeared aeroengine.
The propeller has lots of inertia.
I will try to scheme the possibilityes tomorrow.

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The Hirth solution cannot not be easy to make.
Picture shows five different solutions and the pink parts needs to be carburized and hardened in parts or total surface.
If You wanted to make a fortune small by using a big to make V2 twostrokes and had the choise?

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Niels. A direct geared centrifugal supercharger would work for starting and running. You could then use a 4 stroke type bottom end. With turbo scavenging, an electric fan would work for starting. I think the crankcase pumping is the big flaw in your concept.

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My SV inverted V2 two stroke will have 100mm bore and 150mm stroke and run at MEP of 6.2 bar to make 80 hp at 40 rps and be built with comression ratio of 7,5 to 1 allow use of oktane 92 petrol.

(The Belgian SV Dmotor has 100 mm pistons as well and tolerate 92 oktane in 8 to 1 compression at MEP 10 bar.)

It is possible to make a better combustion chamber with only a single side exhaust valve with than both inlet and exhaust side by side.

I therefore think that Maximun pressure in my V2 running compression ratio 7,5 and MEP 6.2 will be somewhat lower than the Comp 5,9 times MEP 8,5 from the old Argus. 7,5*6.2=46,5 (Angelina) and 5,9* 8,5= 50.2(Argus)
The Argus was/is 15.2 kg/litre so my 2,4 litre Angelina can be surely be 37 kg dry and probably less.

The argument for my original 92mm pistons was to reduce knock incidence and with present day 95 oktane it seems not a problem.100mm pistons make clearance between conrod and liner more easy.

The Dmotor is sold with Compressio 8 and Mep of 10.2 and is 21.5 kg per litre giving some sense of credibility to the other estimates.

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Something along the lines of the May Fireball combustion chamber could be worth looking at. Probably not that extreme, but an assymetric passage to the combustion chamber may help. With a sidevalve, new heads are easy to make...

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I think you are not alone w/ the concept of a side valve for a 2 stroke. It has been in my head now for years, and I bet others here as well. I can't say who, but I have ran this by some engine types, one was no, 2 strokes are dead, the other ya It's been in head, I want to try it. Another a 2 stroke guy couldn't make a case for it via the flow in the head. Research University of Alabama if my memory is correct, a number of students for their graduation added DI to a flathead, and even patented it. 2 exhaust valves and a centrifugal supercharger blowing through the uniflow ports is what I envisioned, for a flat four. Trying it first on a Briggs & Stratton with making both valves the same size, modifying the cam and both valves are exhaust. IMHO maybe there is a case for some sort of stratified charge in the head depending on FI or DI timing. Eon's ago if my memory is correct, there was a flat 2 @ OSH that might have been essentially a Bourke Scottish Yoke 2 stroke w/ flat head valves (a Reed Valve below the Carb for the Crankscase IMMIC). It was smooth as silk, I put my hand on it while it was running on it's stand (with a flywheel) it was like nothing you'd ever experienced. They showed up one year and then gone.